Pump and motor hydraulic system



Feb. 19, 1952 s. B. Mou-:0D

PUMP AND MOTOR HYDRAULIC SYSTEM Filed Sept. 29, 1947 BY My W L ATTORNEYS FIGA.

Patented Feb. 19, 1.9352 l If-gUNlzTED ffsTATEs BA-frgEfNr ii PMPAND Moron HYDRALCSTYSTM stewarti. McLeod;V Dearborn,#Michl-assigner, lby f .raesneJ-fv assignments, i =to lD'etroit'.4v Harvester '1- lompany, L Detroit, Mich., a-L corporation sof Michigan Applicatior-s'epfeiber 29531947, s'eivNuivisfse nfoiaims. (oirsoQsz) A1 g2 vThe present-invention lrelatesetoeahydr-aulic Figuret islam-enlargedf-fragmentaryrsectionof #power-systemland-more particularly to'ahydraulic thevalve structure-showniii-Figure 1. "power unitdesign'ed for use inthe system. l! Referring-now to he `ig'u'res'g inFigure y 1:1 there -"The-inVention-is villustratedlin connection'iirith "-isf'lindicaltedat-5`l0- ornbiiedpumpJa'ndreservoir a pair of hydraulic `mot'ors'-'which -infthe present 5 unit whichcompris'esian electricmotorl l mount- -instance-a'reshown asfpistons-fand cylinders. --ediwithinaifcasingl "whicliiiniturn'issupported fWhile-the system has vmany possibleapplications, fromfa" lloloc1-r-l3 by iii-table securing means such it. is' particularly useful-as a systemior 4'operating L as f the?elongatediatta'ching screws: I 4. =Y1Arrfaper topse'of convertible vehicles. When'used asa' sys- -tured bracket forfattac'hingthef:unittoaafrsuit- #tem forsupplying power-fiorraising-fand' lower-ing'. in able support sirfac dica/edfatl 'thetops of^-convertibl vehicles, itfis-desirable-to -vThe'iblockJ-I 3-!.=atlit pperlfsurfafoe isf-provided -'providefforimanual operation 'ofi=thetopiiin"'lthe Lwith alcylindricalrcess-i 6', asi'lbestlseen.lnlthe eventthat--powerllis not availablefor-operation. @enlargedrscaletillustrateinf'EigureA; whichxire- Accordingly, a Vsystem' has beenlde'vis'ed to permit Il ceives?agearv pump; |152 off-:the typei'ciomprisingean "manual operation 'of the?hydraulicfmotor` in the l5iinterniallyltoothedcylindricalmmber 'andf'anfexl eventof; power failure; fa'ndf further provideslf or Hternallytoothed'piiori'rotatalivl-thereinlimwhich differential/flow of-hydraulicf iid to andf from Jittici-pinion:isprovided'fwithonei'lesstooth than `-'-'the'hyclraulic-m`otor whichis requiredlby the difitheiinternallytootledagear. "The'blook-ili -s'iproference indisplacement-due Atov the presence'fof vided -withvlpass`agfes 518-' -nd,i1ISiLcoInmu'ncating the piston rod in thecylinder. 20c-with Ioppositeis'idesfoff he pfump. `ElA'transvese With the foregoing general remarks in mind,-it passagezg'theroiteriportioncof which sgtapped is an object of the present invention to providea ithereception' asuitable@connectingzdevice, hydraulic 'system for power actuationof Ame'chaf A-rvddtfandicoirmniic'ate wi-ththe pas'sage nism which permits manual manipulation of Ythe 'fill-8. sirr'lil'arpassage communicating withithe mechanism in the event of power failure. 25 passage ="I 9 is provided atflthe oppositsidelof the It is a further object ofthe presentiinvention c to provide, in a hydraulic system,' meanscom pensating for diierential flow of -hydraulicfluid "motbrffl li is'f-iv sib] to and from a uid motor. that mnpassgessficgfhandig| It is a further 'object of thepresent invention 30 adqw to provide a, hydraulic system including `afrevel-'sible pump,a reservoir connected to the pump, valve means controlling the connections` between `the reservoirI and pump, fand additional Vvalve means for controlling the flow of fluid fromfthe.

pump to and from a'hydraulic'motor.

It 'is a further object of the present-'invention `to provide a hydraulic `power unitfhavingwalve :means therein effective to open or close a by-'pa'ss connection to permit vmanual operationof fluid. voperated mechanism in the eventv of powerv failure l svespassagef?) 1s a Y in the hydraulic System A *which-communrcatesiwth-lthemtfibpiane-'res- Other objects and features of the invention :.vaviwillbecome apparent as the description proceeds, LC-afdfinbhelfgdd-LMHIS :lf -especially whentaken in conjunction'with-the rssfaggpI-. auf

accompanying'drawing, wherein:

Figure 1 is a diagrammatic view'of the com pleteY hydraulic systemywith the hydraulic-motors indicated diagrammaticallyand with the.v` pump -and reservoir unit partly in section;

'Figure 2 is an'end 'elevation of Ithe hydraulic power unit employed in the system;

Figurev 3` is a longitudinal section taken vonthe line 3-3 of Figure 2 so as to pass axially through fs'age1'3l r'refjconnected ZtoportseZBandQ especthe 4pump'iand motor 'connections and fao tively? 'by'trarisvers passages "3 Sandff. Bocated the" assagesls "-ifr'ilet for outlet passages; depending incidir tienofrbt within the reduced portion 32 of the transverse passage 3| is a, pin 4| of somewhat greater length than the reduced portion 32 which serves to prevent simultaneous seating of the ball valves 3a and 36. In the intermediate neutral position of the valves when no pressure is being applied thereto by the pump I1 the pin cooperating with the balancing springs 31 will result in both the ball valves 3c and 36 remaining od their respective seats by a, small distance and thereby will permit a restricted iiow of iiuid therepast.

As illustrated, the reservoir 25 is provided with a removable cover 42 secured in place by an elongated bolt 43 which is threaded into a suitably tapped opening at the top or' the valve block 30.

Referring now to Figure 3, the construction of the hydraulic power unit 50i is illustrated. This unit comprises an upper cylindrical casing portion having an apertured supporting bracket 52 secured thereto and a lower generally cylindrical casing portion 53. Casing portions 5I and 53 are secured together in alignment by means of a, reversely bent nange 54 formed on the casing portion 53 which cooperates with an outwardly turned nange 55 on the casing portion 5|. A transverse partition 56 is supported between the nange port-ions 54 and 55. '.Lhe partition 56 is provided with a port 51 which affords communication between the upper valve chamber 5t and the lower valve chamber 59.

Various inlet and outlet connections are provided to the upper chamber 58 and the lower chamber 59. 'lhe upper chamber 53 has a pump connection 60 and a pair or' motor connections 6| and 62, all of these connections being located in the outer cylindrical wall of the casing portion 5|. 'lhe lower chamber 59 is provided with a pump connection 63 which is located in the end wall of the casing portion 53 in alignment with the port 51 formed in the partition 56. In addition, a pair of motor connections 64 and 65 are provided. The connections 60, 6|, 62, 63, 64 and 65 are in the form of internally threaded nipples appropriately secured to openings formed in the walls of the casing portions 5| and 53.

A valve element is provided and has a reduced portion 1I passing through the port 51 and an enlarged portion 12 intermediate the partition and the pump connection 63. The pump connection 63 has a port 13 therein which provides a seat for a ball valve 14 rigidly secured to the lower end of the valve element 10. Inter- -mediate the reduced portion 1| and the enlarged portion 12 of the valve element is a conical portion which is constructed to serve as a valve -in cooperation with the port 51.

The valve 10 is a two-position valve, its iirst position being the lower position, in which case the ball valve 14 seats upon and closes the port 13 formed in the pump connection 63. The second position of the valve 10 is the upper posi-A tion as illustrated in Figure 3, at which time the conical portion 15 of the valve element seats in and closes the port 51 in the partition 56.

Means are provided for moving the valve between its two positions and these means take the form of a solenoid mounted in the upper casing portion 5I and comprising a winding 80 and a core 8| movable axially of the winding. The core 8|, as illustrated in Figure 3, is solid and accordingly substantial forces can be exerted thereon by energization of the winding 80. The solenoid is mounted in the casing portion 5| by an annular plate 82 and by a plug 83 secured 4within a sleeve 84 located within the winding 80.

The core 8| is rigidly connected to the valve 10, the lower end of the core being suitably shaped to receive an enlarged end portion thereof.

A compression spring 86 surrounds the lower end of the core where it extends beyond the winding 80 and engages an annular dished spring seat 81 which is supported in an annular groove adjacent the lower end of the core 8|. The upper end of the spring 86, as illustrated, bears against the sleeve 84.

Referring again to Figure l, the pump and reservoir assembly is connected to a pair of hydraulic motors 90 and 9| through the hydraulic power unit 50. The pump connector 60 on the unit 50 is connected by means of a conduit 95 to the pump passages I9 and 2 I. The other pump connector 63 is connected to the remaining pump passages I8 and 20 by a conduit 96. The motor connectors 62 and 6I are connected respectively to corresponding ends of the cylinders 90 and 9| by conduits 91 and 98 respectively. The motor connecters 64 Yand 65 are connected to the opposite ends of the cylinders 90 and 9| by conduits 99 and |00 respectively.

Before proceeding with an explanation of the operation of the system, attention is directed to the fact that the cylinders 90 and 9| during movements of the pistons |0| and |02 therein will cause a differential flow of hydraulic uid through the conduits 91 and 98 on the one hand and the conduits 99 and |00 on the other hand. This is for the reason that the piston rods |03 and |04 displace a certain amount of fluid from the undersideof the pistons |0| and |02. Accordingly, as the pistons move downwardly, for example, a greater quantity of uid will be flowing through conduits 91 and 92 than will be returning through conduits 99 and |00.

Considering first the operation of the combined pump and reservoir unit, it is assumed first that the pump I1 is rotating in such direction that fluid pressure is built up in passages I9 and 2| and will accordingly cause flow of fluid out of these passages. At the same time, the port 21 and passage 40 in the Valve block 30 are exposed to pressure and accordingly pressure will build up in the right-hand end of the transverse passage 3| (as seen in Figure 4), causing the ball valve 36 to move to the left and engage its seat. Movement of the ball valve 36 to the left moves thc ball valve 35 away from its seat through the rnediurn of the pin 4|, thereby establishing aconnection between the reservoir 25 and the suction side of the pump I1 through the passage 33, the reduced portion 32 of the transverse passage 3i, the left-hand end of the passage 3|, the passage 39 and the port 26. Accordingly, if a differential flow exists between the pressure and suction side of the pump so that more fluid moves through the conduit 95 than is returning through the conduit 96, the deficiency may be made up by iluid withdrawn from the reservoir. If on the other hand operation yof the motor results in the return of more uid through the conduit 96 thanis forced through the conduit 95 by the pump I1, the excess fluid may escape into the reservoir through the ports and passages enumerated. If the motor I I is reversed the operation is identical with the exception that the passages formerly acting as outlet passages now serve as inlet passages.

Suitable circuit-controlling means are provided which insure that when the motor I I is energized to operate motors 90 and 9|, the solenoid windlaisserai iing'f'B-'is also energized. v`Accordingly,Y at lany time that the motor Il is runningfin either-direction to opera-te-` motordll O and 9 I `the solenoid-winding isfenergizedthe' solenoid. core is vmoved .upwardly "as-seen in -Figure l 3 and -the -valve element -'Il throughlthe mot-or connectors `6 I and-BZandthence fi-ntothe upper ends. of thecylinders 19t andi Q I D'o'wnward frnov'e'me'nt of 'the .pistons I il I vand I S2 in the l :cylinders Yresults in the displacement of duidf from beneath fthef vpistons through Ithe foon- Ad-iiits'Sl and Ilintotheniotor connecters-lland 'FBS-respectively. l-l/-lspreviously: stated, the'ball Vvalve 1li -at this time' is folf'the seatf and accordvhing-lythisiluidy escapes through lthe pumpY con- #fn'ecter-SS and returns through the-conduiti-6 to the pump.

If fthe-'motori l I- were reversed the -flow Yoi fluid *would-belfrom the pump through the conduit-96 to-lthe @pump -connec ter d3, thence outwardly through the -motorconnecters VEidY andi through foonduitsBg-and PMI-respectively to the'un'derside N`of-1the cylindersB-and 9|. vFluid displaced from labovethe fpistons-l8land m2 would move from 'thecylinders-S -a-ndlSI through conduits 91 Yand 93 to motor connectersli and EIrespectively and vthenceoutwardly through thepump connecter FE?A and conduit 95 to the pump.

-At any time when .the solenoidwinding 80 .isy

not energized the valve'iJ-is urged to itsrst or lowermost position by vthe compression l'spring "8G-,cat which time a by-pass connection'is establishedbetween the chambers: 53 and 59 through the port 5l'v in the partition. Accordingly, if for :.any-.reasonthere is a failure of electric .power or thesolenoid .8d .cannot .beA energized, it .is .still .possible :.to .effectmanual operation of the. .mech- --anism connected to the. motors .r9 0. andy 9 I Manual'lmovementfoflthe.pistons lill. and iZ inzeither Ldire'ctioninatheir.; cylinders Awillresult in: a yflow .1 of lipid,throughthev conduits 9! and .S8 and.- S9 lzandftl in accordance with the direction oil-movewmentriofthe pistons and there will be a` corree;sponding vflowzof fluid .through .the by-pass port 51 in the partition 56..5Diie1'en'tial iiowof duid n between the conduits ill-and 93 on the' one hand pandthe; conduits 99 .andl on theA other is per- -fmitted since the pump connecter 69 affords open connection tothe reservoir at anytime when Lathe-pumpY I '1. .isfidle. Thence whenpistons Ifi andilliV are manually moved upwardly lasseen in thewgure, thus displacing fluid from the cperatingportion ofthe system, this 'excess fluid v,passes through conduit S5 to the pumpil' and -thence .past the `ball valve 3S through :the pas- -sage`f33 into the reservoir. Upon movement of theapistons Vin Vthe opposite direction the total volume ofthe Operatingv portion of the system is .-increased and the-operating portion of the system remains completely iilled with .fluid as a rezsult` of` ay flow :of .ilu-id .from the reservoir 25 past #then-ball valvef, through the pump I? and thence through theV conduit 95.

efIfthe` pumpV is connected to I.one or more. addi- "itional'f4 hydraulically operated. units such for .eX- ample asfwindowlifters 'ormeansfor sliding the 6 Lmitsiselectivelactuation;fof the#accessoriesingia zyeryidesi-rablef manner. '.Byfwa'ylofexamplefit imayfbe. assumed that ,the pump'is Jconnectedzto a window lifting'zmotorf which preferably-must -be provided'. with' a solenoidoperated control valve. rvWhen .the .solenoid comprising` the wind-ingll and core BI isde-energized, the ball valve-'i4 is on the .valver` seat Y.i3-and. is effectivek to prevent actuation ofthe motors and/QI .whenthe pump' Il.` is operating. .The -pump I'Iwill' therefore befefective tofoperate additional-accessory hydraulic motors. .Moreover, while1the-.closure of thevalveport .'13

vbyl-the-ball-valve M prevents actuation of the motors .90 and SI, it does riot prevent manual operationofthe -device --connected to-these motors since the requisite by-passow of. hydraulic uid `maytake placethroughthe by-pass port'l, `and the flow oflfluidcaused by` differential displacement .at oppositeQsides of the pistons IUI and I 62 may take place as above outlined through the hydraulicv line. 95, which under these conditions is in communication with the interior ofi the reservoir 25.

It will thus be'seen that the apparatus disclosed herein provides leiiicient means for interconnecting a reversible hydraulic pump vto one or more hydraulically operated motors'with provision for permitting'diiferentialsuction and 'discharge'v iiow and with additional'provisionA providing for vinan- 'ual operationof the'hydraulic motor means anc mechanism 'operated 'thereby' in the evento power failure.

v`The drawing and -jthe foregoing vspeciiication 'constitute a ldescription-tof the improved hy- Udraulic -power unit insuch full, clear, concise and exact-terms Vasfto enabley any1-personY skilled in lthe art' to vpractice the=invention', the scope of which'is indicatedfbythe appended-claims.v

What I claimas myfinventiontzis: 1. -A fluid power system comprising a'reversible pump, --a passage-between opposite sides of said pump, Vafluid reservoir connected to said passage, a normally open valve in said passage effective to close said passage to the pressureside of said pump to saidchamber at one side of said partition, .a second. .pump conduit connecting the other .side .of said pump to said- `chamber` at the .v other sideoffsaid partition, afluid motor, a rst motor conduit connection at one side of said partition, asecond Hmotor .conduit connecting the other-side` ofsaid motor to saidchamberV at the other. side .ofY .said partition, and. a two-position v valve in vsaid chambereiectivein the first position to .close one of. .said pump conduits .and in the second position to close said by-pass port.

2. A fluid powerisystem .comprising a reversible pump, a passage between opposite sides of 'said pump, a fluid reservoir connected to said passage, aA normally "open Valve in 'said passage effective to close said passage'to the pressure side of said pump and'to open the passage between thereservoir andthe suctionside of said lpump when said pump is operating, and to open the l passage between the vreservoir and both sidesof .said pump'fwhen saidpump is idle.- a valve Abody 175;.

comprising. a :chamber-f having-. an hinter-mediate partition provided with a luy-pass port therethrough, a first pump conduit connecting one side of said pump to said chamber at one side of said partition, a second pump conduit connecting the other side of said pump to said chamber at the other side of said partition, a liuid motor of the type requiring a differential flow of fluid between inlet and outlet, a rst motor conduit connecting one side of said motor to said chamber at one side of said partition, a second motor conduit connecting the other side of said motor to said chamber at the other side of said partition, and a two-position valve in said chamber effective in the rst position to close one of said pump conduits and in the second position to close said by-pass port.

3. A fluid power system comprising a reversible pump. a passage between opposite sides of said pump, a uid reservoir connected to said passage, a normally open valve in said passage effective to close said passage to the pressure side of said pump and to open the passage between the reservoir and the suction side of said pump when said pump is operating, and to open the passage between the reservoir and both sides of said pump when said pump is idle, a valve body comprising a chamber having an intermediate partition provided with a by-pass port therethrough, a first pump conduit connecting one side of said pump to said chamber at one side of said partition, a second pump conduit connecting the other side of said pump to said chamber at the other side of said partition, a fluid motor of the type requiring a differential flow of fluid between inlet and outlet, a first motor conduit connecting one side of said motor to said chamber at one side of said partition, a second motor conduit connecting the other side of said motor to said chamber at the other side of said partition, a two-position valve in said chamber effective in the rst position to close one of said pump conduits and in the second position to close said by-pass port, resilientmeans urging said valve toward one position and a solenoid effective when energized to move said valve to its other position.

4. A fluid power system comprising a reversible pump, a passage between opposite sides of said pump, a fluid reservoir connected to said passage, a normally open valve in said passage effective to close said passage to the pressure side of said pump and to open the passage vbetween the reservoir and the suction side of said pump when said pump is "operating, and toopen the passage between thereservoir and both sides of said pump when said pump is idle, a valve body comprising a chamber having an intermediate partition provided with a by-pass port therethrough, a rst pump conduit connecting one side of said pump to said chamber at one side of said partition, a second pump conduit connecting the other side of said pump to said chamber at the other side of Wsaid partition, a fluid motor of the type requiring a differential flow of fluid between inlet and outlet, a rst motor conduit connecting one side of said motor to said chamber at one side of said partition, a second motor conduit connecting the other side of said motor to said chamber at the other side of said partition, a two-position valve in said chamber effective in the first position to close one of said pump yconduits and in the second position to close said by-pass port, resilient means urging said valve toward said first position and a solenoid effective when energized to move said Valve to its said second position.

5. A uid power system comprising a reversible pump, an electric motor therefor, a passage between opposite sides of said pump, a fluid reservoir connected to said passage, a normally open valve in said passage effective to close said passage to the pressure side of said pump and to open the passage between the reservoir and the suction side of said pump when said pump is operating, and to open the passage between the reservoir and both sides of said pump when said pump is idle, a valve body comprising a chamber having an intermediate partition provided with a by-pass port therethrough, a first pump conduit connecting one side of said pump to said chamber at one side of said partition, a second pump conduit connecting the other side of said pump to said chamber at the other side of said partition, a uid motor of the type requiring a differential flow of fluid between inlet and outlet, a first motor conduit connecting one side of said motor to said chamber at one side of said partition, a second motor conduit connecting the other side of said motor to said chamber at the other side of said partition, a two-position valve in said chamber effective in the first position to close one of said pump conduits and in the second position to close said b-y-pass port, resilient means urging said valve toward said rst position, a solenoid effective when energized to move said valve to its said second position, and means for energizing said solenoid when said motor is operating to actuate said fluid motor.

6. A uid Valve comprising a valve chamber having an intermediate partition provided with a port therethrough, pump connections at opposite sides of said partition, motor connections at opposite sides of said partition, and a two-position valve in said chamber eiective in its rst position to close one of said pump connections and in the second position to close said port.

7. A iluid valve comprising a valve chamber having an intermediate partition provided with a port therethrough, pump connections at opposite sides of said partition, motor connections at opposite sides of said partition, a two-position valve in said chamber effective in its rst position to close one of said pump connections and in the second position to close said port, resilient means urging said valve toward its first position, and a solenoid effective when energized to lmove said valve to its second position.

8. A fluid valve comprising a valve chamber having an intermediate partition provided with a port therethrough, pump connections at opposite sides of said partition, motor connections at opposite sides of said partition, a two-position valve in said chamber effective in its rst position to close one of said pump connections and in the second position to close said port, resilient means urging said valve toward its rst position, and a solenoid effective when energized to move said valve to its second position, said valve in its rst position opening said port and permitting bypass flow of fluid therethrough to provide for manual operation of motor means connected to said motor connections.

9. A fluid valve comprising a casing having a partition extending thereacross, a port through said partition, pump connections to said casing at opposite sides of said partition, one of said connections being aligned with said port and providing a valve seat in said casing, a twoposition valve element extending through said port having a first valve portion effective in the rst position to seat on said valve seat and having a second valve portion effective in the second position of said valve element to seat on said port.

10. A fluid valve comprising a casing having a partition extending thereacross, a port through said partition, pump connections to said casing at opposite sides of said partition, one of said connections being aligned with said port and providing a valve seat in said casing, a two-position valve element extending through said port having a rst valve portion effective in the rst position to seat on said valve seat and having a second valve portion eiective in the second position of said valve element to seat on said port, resilient means urging said valve element toward its i'lrst position, and a solenoid effective when energized to move said valve element to its second position.

11. A uid valve comprising a casing having a partition extending thereacross, a port through said partition, pump connections to said casing at opposite sides of said partition, one of said connections being aligned with said port and providing a valve seat in said casing, a twoposition valve element extending through said port having a first valve portion effective in the rst position to seat on said valve seat and having a second valve portion effective in the second position of said valve element to seat on said port, resilient means urging said valve element toward its rst position, and a solenoid in said casing having a core connected to said valve element and effective When energized to move said valve element to its second position.

STEWART B. MCLEOD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,307,839 Williams June 24, 1919 2,001,620 Levy May 14, 1935 2,255,878 Dilley Sept. 16, 1941 2,388,755 McLeod Nov. 13, 1945 p 2,437,115 Muller et a1. Mar. 2, 1948 

